This project will optimize an existing innovative method for performing high-throughput screening assays using engineered tissues that mimic the myocardium and a novel, screening instrument that can rapidly measure the mechanical properties of those tissues. Our engineered tissues significantly reduce the need for whole animal testing. In the proposed research, we will focus on refining our heart tissue model growing in a 96-well format. We will produce samples with identical physiological properties that have Z-factors >0.5 in high-throughput screening assays using our screening instrument. We will perform a blind screen using known compounds with known effects on myocardium to evaluate our measure of success. Further, we will test 3 drugs, known to affect cardiovascular functions, using an established toxicity assay and our engineered tissue assay system and correlate the results. Our strategic business partner, Gilson, Inc. (Middleton, WI), which has more than 50 years of business development experience in the life science industry, will collaborate with us on the engineering efforts to improve our screening instrument and develop consumable products with our engineered tissues. After confirming the usefulness and reproducibility of the assay, we will profile a small library of plant extracts from the Philippines. The full library of extracts (16,000 samples) is available only to scientists at the Medical College of Wisconsin who collaborate on this project. NCI has previously screened and ranked the extracts in this library for cytotoxicity on HL60 cells. The sub-library consists of 1,045 extracts that showed the lowest toxicity in the NCI study. We will identify "hit" extracts by their ability to alter 2 important parameters of myocardial contraction measured by our tissue assay system. In Phase II studies, we will focus on characterizing the active components in any extracts that changed myocardial contraction in our assay and screening and profiling the entire library. The ultimate goal of this project is to rapidly and cost-effectively identify an herbal remedy, or compounds from natural products, that could treat cardiovascular diseases. [unreadable] [unreadable] [unreadable]